This document provides technical details on a simplified model for analyzing transient duct flow, including:
- A one-dimensional model is developed using a perturbation of duct exit area to account for friction loss and relate transient to quasi-steady duct velocity with a differential equation.
- Computer programs are included that calculate duct exit momentum through an iterative momentum balance between inlet and outlet, incorporating engine shock loss and additional duct combustion.
- Validation shows the model correlates well with single engine helium and steam test data over a range of chamber pressures.
- Application to full-scale conditions indicates maximum air flow is less than actual Space Shuttle levels, suggesting helium flow alone cannot replicate critical conditions.
P&w tables of compressible flow functionsJulio Banks
Compressible-flow Mach Functionas
Page 5 - Nomenclature
Pages 6 & 7 - Mach Functions
Recommendaitons: Used Equations on Pp. 6 & 7 to
generate any of the results from the table as functions
of specific heat ration, Gamma = Cp/Cv.
Enjoy it as one would enjoy their favorite music.
This presentation had been prepared for the aircraft propulsion class to my undergraduate and graduate students at Kasetsart University and Chulalongkorn University - Bangkok, Thailand.
P&w tables of compressible flow functionsJulio Banks
Compressible-flow Mach Functionas
Page 5 - Nomenclature
Pages 6 & 7 - Mach Functions
Recommendaitons: Used Equations on Pp. 6 & 7 to
generate any of the results from the table as functions
of specific heat ration, Gamma = Cp/Cv.
Enjoy it as one would enjoy their favorite music.
This presentation had been prepared for the aircraft propulsion class to my undergraduate and graduate students at Kasetsart University and Chulalongkorn University - Bangkok, Thailand.
SPLIT SECOND ANALYSIS COVERING HIGH PRESSURE GAS FLOW DYNAMICS AT PIPE OUTLET...AEIJjournal2
A detailed investigation covering piped gas flow characteristics in high pressure flow conditions. Such flow analysis can be resolved using established mathematical equations known as the Fanno condition, which usually cover steady state, or final flow conditions. However, in real life, such flow conditions are
transient, varying with time. This paper uses CFD analysis providing a split second “snapshot” at what happens at the pipe outlet, and therefore, a closer understanding at what happens at the pipe’s outlet in high pressure gas flow condition
Flash Steam and Steam Condensates in Return LinesVijay Sarathy
In power plants, boiler feed water is subjected to heat thereby producing steam which acts as a motive force for a steam turbine. The steam upon doing work loses energy to form condensate and is recycled/returned back to reduce the required make up boiler feed water (BFW).
Recycling steam condensate poses its own challenges. Flash Steam is defined as steam generated from steam condensate due to a drop in pressure. When high pressure and temperature condensate passes through process elements such as steam traps or pressure reducing valves to lose pressure, the condensate flashes to form steam. Greater the drop in pressure, greater is the flash steam generated. This results in a two phase flow in the condensate return lines.
This power point presentation has for post graduate student in mechanical engineering in thermal engineering. This presentation is quite simple and perfect to explain the axial flow compressor and fan.It is the best presentation.
Lecture notes from my BSMET Heat Transfer Course in Heat Transfer at WIT (Wentworth Institute of Technology), Boston, Massachusetts.
It is intended to be utilized by persons interested in the subject of heat transfer as a self-study course.
I am much appreciative of my education at WIT and wish the interested student the best experience in the pursuit of such a practical and beautiful branch of science and engineering.
My WIT and Tufts University (Medford, Massachusetts) has afforded me a quite comfortable standard of living and I wish to share such an experience with those interested in the subject matter of Heat Transfer.
The one page document was located at http://www.chirozone.net/TheDivineMatrix.pdf. I simply show the equation to illustrate the power of the caring individuals, "intenders" or "givers". Simplified states take the square root of the population intended to be affected by the intenders, then divide it by 10. For instance, if we want to affect 100 people, taking the square root produces 10 which divided by 10 results in one. Yes, the power of one rule. We can make a change in the world by simply believing that we can. See "The Power of Awareness" which can be summarized as follows:
The shadow effect enlightenment based upon “The Power of Awareness” *
“ it is only when we have the courage to face things exactly as
they are without any self-deception or illusion that the light
will develop out events by which the path to success may be
recognized”
I Ching
SPLIT SECOND ANALYSIS COVERING HIGH PRESSURE GAS FLOW DYNAMICS AT PIPE OUTLET...AEIJjournal2
A detailed investigation covering piped gas flow characteristics in high pressure flow conditions. Such flow analysis can be resolved using established mathematical equations known as the Fanno condition, which usually cover steady state, or final flow conditions. However, in real life, such flow conditions are
transient, varying with time. This paper uses CFD analysis providing a split second “snapshot” at what happens at the pipe outlet, and therefore, a closer understanding at what happens at the pipe’s outlet in high pressure gas flow condition
Flash Steam and Steam Condensates in Return LinesVijay Sarathy
In power plants, boiler feed water is subjected to heat thereby producing steam which acts as a motive force for a steam turbine. The steam upon doing work loses energy to form condensate and is recycled/returned back to reduce the required make up boiler feed water (BFW).
Recycling steam condensate poses its own challenges. Flash Steam is defined as steam generated from steam condensate due to a drop in pressure. When high pressure and temperature condensate passes through process elements such as steam traps or pressure reducing valves to lose pressure, the condensate flashes to form steam. Greater the drop in pressure, greater is the flash steam generated. This results in a two phase flow in the condensate return lines.
This power point presentation has for post graduate student in mechanical engineering in thermal engineering. This presentation is quite simple and perfect to explain the axial flow compressor and fan.It is the best presentation.
Lecture notes from my BSMET Heat Transfer Course in Heat Transfer at WIT (Wentworth Institute of Technology), Boston, Massachusetts.
It is intended to be utilized by persons interested in the subject of heat transfer as a self-study course.
I am much appreciative of my education at WIT and wish the interested student the best experience in the pursuit of such a practical and beautiful branch of science and engineering.
My WIT and Tufts University (Medford, Massachusetts) has afforded me a quite comfortable standard of living and I wish to share such an experience with those interested in the subject matter of Heat Transfer.
The one page document was located at http://www.chirozone.net/TheDivineMatrix.pdf. I simply show the equation to illustrate the power of the caring individuals, "intenders" or "givers". Simplified states take the square root of the population intended to be affected by the intenders, then divide it by 10. For instance, if we want to affect 100 people, taking the square root produces 10 which divided by 10 results in one. Yes, the power of one rule. We can make a change in the world by simply believing that we can. See "The Power of Awareness" which can be summarized as follows:
The shadow effect enlightenment based upon “The Power of Awareness” *
“ it is only when we have the courage to face things exactly as
they are without any self-deception or illusion that the light
will develop out events by which the path to success may be
recognized”
I Ching
Three types of lies which should not apply to simulationsJulio Banks
This white paper is intended to encourage simulation engineers to be good steward of their talent to understand the art of simulation. Additionally, I hope that the reader will also greatly appreciate the effect of "misusing" their talent to make a story that is not real or true whether such an activity is intentional or inadvertent. The question that I am urging the reader to ask himself or herself is this, "Can a person falling 2 inches while seating in a cushion seat have biomechanical damage to the spinal cord unless such a person has had a pre-existing condition such as a 'herniated disc' versus our own experience that people often times, even ourselves, have fallen a couple of feet as when we play the game of pulling a chair from our 'play frineds' unbeknownst to them and simply laugh when they 'fall flat on their posterior' but we never recall anyone of us being suit because 'our buddy filed a claim against us for 'pulling the chair causing the 'damaging fall"
Seek the truth, report it the best one can, this is the essential ingredient of a truly objective analyst.
"Yo Creo", the author's avatar (virtual) name, has the dual meaning, in Spanish, "I believe" and "I create". Therefore I encourage the reader of this paper to ponder on this idea, that simulating is an art in which one must believe that one can can create anything they set themselves to achieve; that is, a thought is a virtual world while the actualization of such thoughts create our physical reality.
This paper is WIP (Work In Progress) is intended to inspire the curiosity of those individuals interested in the transient heat transfer phenomena. The use of the relatively simple TDMA (Tri-Diagonal Matrix Algorithm), aka, Thomas Algorithm has been used for a transient heat transfer solution but it has also been successfully implemented in solution of steady state heat transfer problems with variable properties of cooling fluid (advection) and convection as well as the thermal conductivity of TBC (Thermal Barrier Coatings) and metals.
Math cad ROR solution using a biquadratic bypass methodJulio Banks
This file shows the solution of a ROR (Rate Of Return) using a symbolic solution of a
biquadratic bypass method. The solution is given in terms of a variable, w, appearing
twice in a polynomial of the form. w raised to the 2p, and w raised to the p with a
nontrivial constant. Letting x = w raised to the pth-power as a bypass variable, then a
quadratic bypass equation is solved for x. Since the original root is w, then one must
perform a post-process of x to transform the x-root to the w-root solution sought. It should be noted that the intermediate bypass parameter, w, was eliminated from the
numerical solution.
Conclusion
The objective of this report is to promote the recognition of biquadratic equations
and therefore eliminate the unnecessary iterative procedure otherwise required in
the absence of a closed-form root finding solution. This goal has been achieved in
this report via the utilization of the biquadratic equation solution method.
Probability basis of safe life evaluation in small airplanes by w. michael reyerJulio Banks
Probability Basis of Safe-Life Evaluation in Small Airplanes by W. Michael Reyer. I was not able to locate this file in the Internet and therefore, I uploaded a version I scanned from my personal library
Ramberg-Osgood - 17-4 PH SS(Stainless Steel) as a Function of TemperatureJulio Banks
Ramberg-Osgood - 17-4 PH Stainless Steel As A Function of Temperature. This paper demonstrate a method of creating stress-strain functions using the Ramberg-Osgood equation with its parameters made into functions of temperature in a given temperature range. Ultimately, the equation can be utilized to obtain the nonlinear effective stress and stain in highly localized areas of strain (or stress) concentrations using the ESED (Equivalent Strain Energy Density) method aka Glinka (from George Glinka). Finally, the life of a metal part can be evaluated. The ESED is a method of circumventing the use of Nonlinear stress analysis. It should be noted that some FEA software such as NEi Nastran can solve a linear FEA with "local nonlinear regions" and such approach may be advisable although it is an obscured method since the analyst must trust that his or her model does capture the intended "non linear portion of his or her FEA model". It is recommended to apply the ESED to a solution first, then execute the FEA model in which the nonlinear region is established then compare the results. The agreement should between the ESED and the FEA should be not greater than 5%.
The New Engineering by Mr. Eugene F. AdiutoriJulio Banks
Mr. Eugen F. Adiutori has been promoting his work since
1964. Since his findings are a paradigm shift, it has yet
to find a discerning audience to appreciate his findings.
The file is available to the public at Mr. Adiutori's web
site: http://thenewengineering.com/BookTNE.pdf.pdf
It is my hope that Mr. Adiutori will find a discerning
audience who would apply his methods to the solution
of engineering problems for the good of humanity.
This MathCAD file report predicts the transient skin temperature of a missile as it traverses the different layers of the atmosphere. The heat transfer coefficient is function of the height, z,t of the missile since the pressure and temperature of the are function of z,
Experimental Investigations and Computational Analysis on Subsonic Wind Tunnelijtsrd
This paper disclose the entire approach to design an open circuit subsonic wind tunnel which will be used to consider the wind impact on the airfoil. The current rules and discoveries of the past research works were sought after for plan figuring of different segments of the wind tunnel. Wind speed of 26 m s have been practiced at the test territory. The wind qualities over a symmetrical airfoil are viewed as probably in a low speed wind tunnel. Tests were finished by moving the approach, from 0 to 5 degree. The stream attributes over a symmetrical airfoil are examined tentatively. The pressure distribution on the airfoil area was estimated, lift and drag force were estimated and velocity profiles were acquired. Rishabh Kumar Sahu | Saurabh Sharma | Vivek Swaroop | Vishal Kumar ""Experimental Investigations and Computational Analysis on Subsonic Wind Tunnel"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23511.pdf
Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/23511/experimental-investigations-and-computational-analysis-on-subsonic-wind-tunnel/rishabh-kumar-sahu
This paper deals with the numerical analysis of 3d model which has inlet port diameter 46mm,valve diameter 43mm and the length and diameter of the cy linder is 562mm and 93.65mm respectively which is developed to study the effect of valve lif t on the flow of fluid inside the cylinder. For different valve lifts velocity will change inside t he cylinder. Results of CFD simulation indicated th at valve lift affects velocity flow field inside the c ylinder. It also proved that CFD is a convenient to ol for designing and optimizing the flow field in the engine.
Design Considerations for Antisurge Valve SizingVijay Sarathy
Centrifugal Compressors experience a phenomenon called “Surge” which can be defined as a situation where a flow reversal from the discharge side back into the compressor casing causing mechanical damage.
The reasons are multitude ranging from driver failure, power failure, upset process conditions, start up, shutdown, failure of anti-surge mechanisms, check valve failure to operator error to name a few. The consequences of surge are more mechanical in nature whereby ball bearings, seals, thrust bearing, collar shafts, impellers wear out and sometimes depending on the how powerful are the surge forces, cause fractures to the machinery parts due to excessive vibrations.
The following tutorial explains how to size an anti-surge valve for a single stage VSD system for Concept/Basic Engineering purposes.
CONTROL VALVE SIZING AND SELECTION FOR ANY APPLICATION.pptNagalingeswaranR
CONTROL VALVE BASICS.INCLUDING SIZIND, DETAILING AND SELECTION OF MATERIAL.THIS IS APPLICABLE FOR ALL APPLICATIONS LIKE UTILITY, POWER, WATER AND REFINERY. FROM THE PRESENTATION THE DESIGN ENGINEER CAN DECIDE THE TYPE OF CONTROL VALVE AND ITS CHARACTER TO BE SELECTED FOR THE GIVEN APPLICATION.
Studies on impact of inlet viscosity ratio, decay rate & length scales in a c...QuEST Global
Modern aircraft engine designs are driven towards higher operating temperature and lower coolant flow requirements. During the flight mission, the hot gas path components encounter flows at different pressure, temperature and turbulence conditions. During design of such components, there is always an interest towards fundamental understanding of the impact of inlet turbulence on overall performance. The paper presents aerodynamic performance (stage efficiency) impact of stator inlet viscosity ratio, decay rate and length scales in a cooled turbine rig, based on CFD studies only. Through CFD studies, it is observed that an inlet length scale variation by 10 times could impact the aerodynamic efficiency by ~0.5% to 4% depending on the size of the length scale. Efficiency drops with higher flow length scales and turbulence intensity. The length scale effects are observed to be more predominant with high turbulence intensities than at low turbulence intensities. Similarly a viscosity ratio increase by 1000 times can decrease efficiency by < 0.5% in the lower bounds and can drastically increase to ~ 3% at higher bounds. The efficiency drop can be as much as 2.5 % for a decay rate change from 0.01 to 1 for viscosity ratio of 10000.
Numerical Calculation of Solid-Liquid two-Phase Flow Inside a Small Sewage Pumptheijes
Based on a mixture multiphase flow model,theRNG k–εturbulencemodelandfrozen rotor method were used to perform a numerical simulation of steady flow in the internal flow field of a sewage pump that transports solid and liquid phase flows. Resultsof the study indicate that the degree of wear on the front and the back of the blade suction surface from different densities of solid particles shows a completely opposite influencing trend. With the increase of delivered solid-phase density, the isobaric equilibrium position moves to the leading edge point of the blade, but the solid-phase isoconcentration point on the blade pressure surface and suction surface basically remains unchanged. The difference between hydraulic lift and water lift indelivering solid- and liquid-phase flows shows a rising trend with the increase of working flow
Using Computational Fluid Dynamics as a tool for improved prediction of press...ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Similar to Nasa tech briefs ksk 11495, simplified model of duct flow (20)
Apologia - A Call for a Reformation of Christian Protestants Organizations.pdfJulio Banks
This document shows how to know whether an organization claiming to be IRS 501(C)(3) tax exempted nonprofit is being partisan by teaching that the republican party is the party of Jesus Christ violating the nonpartisan IRS requirement are false Christian organizations.
The treatment of large structural systems may be simplified by dividing the system into
smaller systems called components. The components are related through the
displacement, and force conditions at their junction points. Each component is represented
by mode shapes (or functions).
The synchronicity time or common time of two (2) independent and asynchronous events can be readily
completed in a four (4) steps algorithm to be described in this article. Additionally, two (2) illustrative
examples are also provided for completeness of presentation of the Synchronicity Algorithm.
Math cad prime the relationship between the cubit, meter, pi and the golden...Julio Banks
It has been reported that the ancient Egyptians knew pi, the golden ration (phi) and the meter. This paper summarizes the relationship of pi, and phi via the cubit.
Jannaf 10 1986 paper by julio c. banks, et. al.-ballistic performance of lpg ...Julio Banks
This paper is the result of the response of LPG (Liquid Propellant Gun) to high-temperate simulated-desert condition using ANSYS FEA (Finite Element Analysis) and Mica Heating Banks.
web site: http://www.joycenter.net/wp-content/uploads/2013/04/Mans-Search-for-Meaning-Viktor-Frankl.pdf
A case can be made that since the main basis of "The Theory" of evolution is the "Self-preservation principle". That is, how could the propagation of the a specie be enhanced by the demeaning action of a group against its constituents and even self-against-self. The only explanation is that humas were created and not a result of a random sett of actions causing consciousness arriving from non-conscious matter. Life comes from life, and intelligence (DNA), comes from intelligence. This book can be contrasted with: The Lucifer Effect Understanding How Good People Turn Evil by Philip Zimbardo' and also with the Bible for a view of The Meaning of Life from ancient to contemporary writings for balance understanding of the physical (Psyche) to the metaphysical (Spiritual). We can view the human condition as the effect of gravity of interacting physical objects and human interaction as the response to spiritual influence (angels and demons).
When the Scriptures command us to “love your enemies”, “bless those who curse you” as well as “Judge not because as you judge you will also be judged and the very same standard you apply in condemning others you also be condemned”. One can see, in the context of this essay, that we are actually harming ourselves if we do not love our “perceived enemies” since it is well known that “There are no greater flaws than the ones we perceive in others than the ones residing within ourselves (known as “our personal demons” or “small judging sub-self)”. This is in essence the basis of psychological projection which is a form of psychological dissonance (the closer one is to danger, the more one tends to minimize or even ignore its potential harm to us). Psychological dissonance is a defense mechanism by which “the human mind minimizes the pain of being less than the person that we all believe we are and we seek to find. The true self is the enlightened being who has discovered the meaning of love. Finally, we are home when we feel at peace at being who we are; unique individuals just as our DNA and fingerprints identifies us from billions of other humans. Be yourself and celebrate your uniqueness then you will be truly enlightened - you have arrived at the place call true self and therefore happy
The first step required to defeating an enemy is by first thoroughly defining it. A physician runs tests of their patients to determine the type of pathogen ailing such patients. Similarly, we must be clear that A Muslim Terrorist is indeed a Fundamentalist and not a Radical Terrorist since the method of striking terror is explicitly and clearly defined in the Qur'an. Christianity is the only religion that needs not attack any other religion such as the Islam religion since God is the author and finisher of our faith and also commands the Christians to allow God to avenge Himself for our attacks even from Islamic Terrorist. A Christian is commanded to live at peace with all humans and when such a peaceful coexistence is not achieved then we must simply stay away from such toxic humans.
The primary test for a true religion is that "The Judeo-Christian God does not need nor require that mere mortal human beings to defend Him".
NASA-TM-X-74335 --U.S. Standard Atmosphere 1976Julio Banks
NASA-TM-X-74335 --U.S. Standard Atmosphere 1976. This information is useful for airframes (e.g., missiles and aircrafts) aero-thermos analysis and design.
Mathcad P-elements linear versus nonlinear stress 2014-t6Julio Banks
This work couples the classical ESED (Equivalent Strain Energy Density) Method; aka, Glinka. The most expedient method of solving a structural problem using FEA (Finite Element Analysis). There would be occasions when stress concentrations would be calculated due to interior corners, holes, sudden change of geometry (aka stress raisers). Although some software would allow regions in the vicinity of such stress risers to be defined by nonlinear material models such as "Elastic Perfectly-plastic", "Bilinear (Elastic and linear plastic), or the fundamental Ramberg-Osgood metal strain-stress models. Once the Linear-elastic FEA solution is obtained one can readily determine that Pseduo nonlinear strain, the corresponding stress and the implicit stress-intensification factor, Kt. It should be noted that once the analyst-designer is ready for final analysis, it would be most prudent to create a FEA model in which the regions of high concentration of stress to be modeled with local nonlinear models of the metal using St. Vennants' Principle of load-and-resistance distance from area of interest. The P-method is an excellent FEA element that can "find the actual nonlinear stress" by the simple iterative increase of the order of the polynomial representing the stress fields within every P-element. It should be noted that this research was facilitated by the use of the P-element FEA software called StressCheck which is 100% P-element solution which I am quite pleased to have had the opportunity of utilizing for this research.
Apologia - The martyrs killed for clarifying the bibleJulio Banks
I know all the things you do, that you are neither hot nor cold. I wish that you were one or the other! 16But since you are like lukewarm water, neither hot nor cold, I will spit you out of my mouth!” - Revelation 3:15-16
“A man who does not have something for which he is willing to die is not fit to live.” - Martin Luther King Jr.
Spontaneous creation of the universe ex nihil by maya lincoln and avi wasserJulio Banks
Questions regarding the formation of the Universe and ‘what was there ’ before it came to existence have
been of great interest to mankind at all times. Several suggestions have been presented during the ages –
mostly assuming a preliminary state prior to creation. Nevertheless, theories that require initial conditions
are not considered complete, since they lack an explanation of what created such conditions. We therefore
propose the ‘Creatio Ex Nihilo ’ (CEN) theory, aimed at describing the origin of the Universe from ‘nothing ’ in
information terms. The suggested framework does not require amendments to the laws of physics: but rather
provides a new scenario to the Universe initiation process, and from that point merges with state-of-the-art
cosmological models. The paper is aimed at providing a first step towards a more complete model of the
Universe creation – proving that creation Ex Nihilo is feasible. Further adjustments, elaborations, formalisms
and experiments are required to formulate and support the theory.
The “necessary observer” that quantum mechanics require is described in the b...Julio Banks
This essay is intended to share the vies of the author of his Judeo-Christian belief and the physical validation of such believes based upon the theories of Quantum Mechanics.
A fund way to remember how to "fix our manifested creation" by means of observation is as follows: "Keep an eye on the ball", "Do not drop the ball"
Advances in fatigue and fracture mechanics by grzegorz (greg) glinkaJulio Banks
Professor Grzegorz (Greg) Glinka has made substantial contributions to the field of stress concentration evaluation using linear FEA results using the ESED (Equivalent Striain Energy Density). ESED aka Glinka methods allows the determination of strain-stress state at a point of local concentration by equating the strain energy from the linear FEA area in the material strain-stress curve to that of the actual strain-stress of the material using a models such as Ramberg-Osgood. The ESED method is more accurate than the Neuber requiring the equating of SED (Strain Energy Densities) of linear FEA results that Stress is proportional to strain even when the FEA predicts a stress greater than the ultimate strength of the material. One easy method of remember when to use ESED versus Neuber is that ESED, more accurate, should be use on the stress analysis of rocket structures and Neuber delegated to aerospace engines and components.
Dive into the innovative world of smart garages with our insightful presentation, "Exploring the Future of Smart Garages." This comprehensive guide covers the latest advancements in garage technology, including automated systems, smart security features, energy efficiency solutions, and seamless integration with smart home ecosystems. Learn how these technologies are transforming traditional garages into high-tech, efficient spaces that enhance convenience, safety, and sustainability.
Ideal for homeowners, tech enthusiasts, and industry professionals, this presentation provides valuable insights into the trends, benefits, and future developments in smart garage technology. Stay ahead of the curve with our expert analysis and practical tips on implementing smart garage solutions.
Can AI do good? at 'offtheCanvas' India HCI preludeAlan Dix
Invited talk at 'offtheCanvas' IndiaHCI prelude, 29th June 2024.
https://www.alandix.com/academic/talks/offtheCanvas-IndiaHCI2024/
The world is being changed fundamentally by AI and we are constantly faced with newspaper headlines about its harmful effects. However, there is also the potential to both ameliorate theses harms and use the new abilities of AI to transform society for the good. Can you make the difference?
Between Filth and Fortune- Urban Cattle Foraging Realities by Devi S Nair, An...Mansi Shah
This study examines cattle rearing in urban and rural settings, focusing on milk production and consumption. By exploring a case in Ahmedabad, it highlights the challenges and processes in dairy farming across different environments, emphasising the need for sustainable practices and the essential role of milk in daily consumption.
Hello everyone! I am thrilled to present my latest portfolio on LinkedIn, marking the culmination of my architectural journey thus far. Over the span of five years, I've been fortunate to acquire a wealth of knowledge under the guidance of esteemed professors and industry mentors. From rigorous academic pursuits to practical engagements, each experience has contributed to my growth and refinement as an architecture student. This portfolio not only showcases my projects but also underscores my attention to detail and to innovative architecture as a profession.
Expert Accessory Dwelling Unit (ADU) Drafting ServicesResDraft
Whether you’re looking to create a guest house, a rental unit, or a private retreat, our experienced team will design a space that complements your existing home and maximizes your investment. We provide personalized, comprehensive expert accessory dwelling unit (ADU)drafting solutions tailored to your needs, ensuring a seamless process from concept to completion.
Top 5 Indian Style Modular Kitchen DesignsFinzo Kitchens
Get the perfect modular kitchen in Gurgaon at Finzo! We offer high-quality, custom-designed kitchens at the best prices. Wardrobes and home & office furniture are also available. Free consultation! Best Quality Luxury Modular kitchen in Gurgaon available at best price. All types of Modular Kitchens are available U Shaped Modular kitchens, L Shaped Modular Kitchen, G Shaped Modular Kitchens, Inline Modular Kitchens and Italian Modular Kitchen.
Nasa tech briefs ksk 11495, simplified model of duct flow
1. John F. Kennedy Space Center
Kennedy Space Center, Florida 32899
Technical Support Package
Simplified Model of Duct Flow
NASA Tech Briefs
KSC-11495
NIS/
National
Aeronautics and
Space
Administration
2. Technical Support Package
For
SIMPLIFIED MODEL OF DUCT FLOW
KSC-11495
NASA Tech Briefs
The information in this Technical Support Package comprises the
documentation referenced in KSC-11495 of NASA Tech Briefs. It is
provided under the Technology utilization Program of the National
Aeronautics and Space Administration to make available the results
of aerospace-related developments considered to have wider
technological, scientific, or commercial applications.
Additional information regarding research and technology in this
general area may be found in Scientific and Technical Aerospace
Reports (STAR) which is a comprehensive abstracting and indexing
journal covering worldwide report literature on the science and
technology of space and aeronautics. STAR is available to the
public on subscription from the Superintendent of Documents, U.S.
Government Printing Office, Washington, D.C. 20402.
NOTICE: This document was prepared under the sponsorship of the
National Aeronautics and Space Administration. Neither the United
States Government nor any person acting on behalf of the united
States Government assumes any liability resulting from the use of
the information contained in this document or warrants that such
use will be free from privately owned rights.
3. SIMPLIFIED MODEL OF DUCT FLOW
INTRODUCTION
Analysis of the safety of hydrogen disposal in the Space Shuttle Main Engine
exhaust duet at Vandenberg was made difficult by the complexity of the transient fluid
flow through the duct at critical times. Finite element analysis gave information on
overall trends and on local flow, but did not match test data very well, and was much
too expensive to u~e for adjusting input to match data.
A simple one-dimensional program was developed, using a perturbation of duct exit
area to account for duct friction loss, which could be used to iterate aspiration until
inlet and exit momentum are balanced. The transient flow can then be calculated as a
perturbation of the quasi-steady (equilibrium) flow computed by iteration. Only after
the total transient airflow through the duct is known, can local conditions for
combustion or explosion be evaluated.
'- DESCRIPTION
~
~ A description of the analysis and listings of the computer programs is given in
~, MCR-81-536, No. 084859, Vol. 1, 1/1-Scale VLS Duct Steam Inerting System, Phase III
~ Tests, Appendix C, which is attached. Also attached is a copy of Section 1.5 - Task V
{ Duct Transient Tests, from the same report, which~hows the application of this
~ analysis to the actual problem.
~ The first novel feature of this analysis is the inclusion of duct friction loss in
an effective duct exit arca, so that the inviscid conservation of inlet momentum can
.~ be used to make the solution iteration very simple. The second novel feature is
~ relating the transient duct velocity to the quasi-steady state (equilibrium) velocity
~ with'a simple differential equation. This separation of transient and equilibrium
~ velocity enormously simplifies the converg~nce problem.
~ However, the most important aspect of this work is to again demonstrate that the
J~simplest analysis that captures the important features of a problem is the best
analysis.
,APPLICATIONS
This technique is applicable to any situation in which the knowledge of the
transient behavior of average fluid parameters is important, and for situations in
which finite element analysis is impractical beca~se of time or cost.
The same technique c.an be extended to any' situation in which 'the average
properties of a solution to sets of partial differential equations is required,
and in which finite difference solutions ar~ impractical. In practice, this
usually means solutions in at least three dimensions.
KSC-11495
-1
4. MCR-87-536, No. 084859, Vol.
Duct Stream Inerting System,
1, 1/7-Scale VLS
Phase III Tests
APPENDIX C
AIR ENTRAINMENT ANALYSIS
The a~entrainmen[ analysis requires establishment of a uasi-stead flowrate driven by the
SSME and steam nozzle flows. A momentum balance iterauon between ~t inlet and exit.
incorporating the engine and SIS flows and including aerodynamic shock loss of engine
momentum, provides the quasi-steady velocities through the operational envelop~_ O~ce the
quasi-steady velocities are calculated, ttansient velocities can be calculated_ An iteratIon to
match transient velocity is used to determine the total duct airflow. Acceptable results are
provided by a conscious effon to keep the analysis as simple as possible, emphasizing fIrst-order
effects and one-dimensional flow_ Data from the Martin Marietta In-scale test series suppons
the analysis.
The equation for the ll-nnsient duct ,oelocit)· can be simply exp,·cssed in terms
of the equilibrium duct ,,-elocity in the follolin<g marlnero
If the duct velocity is defined to be the duct exil velocity, Dnd it tho .
entrance lbss and the friction loss within the ducl arc expressed in terms of
the duct exit dynamic pressure, then
pll~
-- = exit dynamic pressure = exit loss
2g
.K(p;:2}.....tmtrancelOss~..·friction·lOss
pv 2
(1+K)-2< - ·tota.! duct loss.
g . <
If 'the flow is in equilibrium, the duct equilibrium velocity will be that velocity
which results in a duct loss which results in a duct exit static pressure which
is just equal to the ambient. pressure. The force available to accelerate or .
decelerate the fluid in the duct is just "the difference between the equilibrium
duct. loss and t.he transient duct loss times the exit area, or
.i Lp . •
m = - = mass Within the duct
g
The rate-ot-change of the duct velocity is just the acceleration of the mass in
the duct, which in t.urn is just the ratio of the force to the mass.
dV . {l+K)F-=a=-= (V2 _V2)
dt m' 2L It
KSC-i149~f'
5. The duct pressure loss coefficien[~ K, is determined using steam-air and helium-air test data.
Values of K are selected for the computation of velocities arising from a known system flow and
the resulting entrained air flow.
. . dv
V<t+~t) = V(t)+~t· dt
where
dv =(1+K)<Y2 _y2)
dt 2L 'f
and .K =Duct Resistance Coefficient
L =Duct Length
V.. = Duct Quasi-Steady Velocity
V =Duct Velocity
These resulting velocities are compared against velocities computed from pitot pressure
measurements for discrete locations in Plane D (Figures 7-13, -14, -15). Once K is known for
the duct geometry, it is independent ofvariatio'1 in gas mixture concentrations or scale factor and
can be used for full size prediction.
The quasi-steady duct flow and velocity obtained for each time step of the launch abon sequence
(shutdown from RPL), shown in Figure C-1, are calculated using a momentum balance between
the planes of the duct inlet and exiL Duct friction losses are incorporated when calculating exit
momentum. The total duct resistance loss is the sum of friction loss, as ratioed to the duct exit
dynamic head,
pvi
2 '
and the dumping loss, which is the duct exit dynamic head. The total resistance is then
PV2
(I+K)--t.
KSC-11495
-2A
6. Scenario: Three Engines at RPL I
Engine...
-E 160
::5 -4l
c::
'c;,-... 140 c::::t: w
...~ 0
c:: 120 ....4l
at i90 c::
at
~ 100 C;;>
c::::t:
...':I 80
0
v .:J
:CI); I...lit
60(!I
Shutdown Sequence-No.1, No.2. No.3
Eu.. 139 :;/, Max Detrimental
.,
o Unburned GH~ Flow Rate
E
...
- ~~--~--------------------
E
u..
, ......
..........
C(H11bined Detrimental
-0 Unburned GHl
-
1 ............... /
all ".
w ..~ •••••/
"t2 ........, ..... .....-:-~-....... / ..... ......,
4l
40c::
:; /' fQ.., :~>/ ....··B .(.:" ',.....'l-.......-J.....- ............... .....................
.Q
c:: / ._..."" '. .... "filii'" -_. ......0 ..... - ,
::l 20
. L Engine 1 Engine 2 Engine 3 ........, '.'0. ,
Profile Profile Profile ., '. ,0
o 1 2 3 4 6 7
Time. I
Figure C..l. FRF Shutdown Sequencefrom RPL (Case 2)
Now, suppose the actual exit area is divided by the factor (l+K)1IZ so that the exit velocity is
increased by the same factor. The exit dynamic head will be increased by the factor (1 + K) so
that the dumping loss with the adjusted exi ~ area is exacdy equal to the acmal total duct
resistance. Thus a simple equality ofinlet and exit momenmm can be used to iterate a solution
to determine the aspirated air flow•. The Manin Marietta steamaair tests are used to evaluate the
effective inlet momentum of the steamjets, using the same adjusted exit area and thus
accounting for duct friction loss in that evalu~tion.
rilvOUT =(rilAIJI +1i1.m:.w+m".o)vour
Iilvour(l + K.)1IZ =thvlN'
where IilvlN' = mvlla0+mvAIII.
with vAlR =0
Once steam momentum is known, the momenmm of propellants at full scale or helium at
In-scale injected through the SSME nozzles can be added. Evaluation of the nozzle flow
momentum entering the duct is uncenain because of the variation in shock train losses as the
-engine chamber pressure drops. A simple, conservative (approximately 6% greater loss than
calculating multiple shocks) procedure is used (Ref 1). The ratio ofentrained air to engine
propellant flow is 6.28 with a shock versus a ratio of9.72 without the shock. This is consistent
with previous results of 6.0 obtained at MSFC. The nozzle exit flow passes through a single,
normal shock to get[IhC appro:riatc ]IOSS in total pressure,
* (M-2)''''
Pc =Pc •
(.!tM2_!:!}T-.
1+ I 1+1
KSc-11495
-3A
'.
7. where
and Pc =engine chamber pressure
p. = ambient pressure.
The flow is then expanded back to a static pressure equal to ambient to get an adjusted Mach
number
M* is a dimensionless velocity ratio (Ref 2)
fonned with the speed of sound at sonic conditions (M = 1) -so that for a given chamber
temperature, M* is proportional to velocity. Thus the ratio
is just the effect of shock loss on flow velocity, where
,
Since momentum is mass flow times velocity, the M* ratio is also the effect of the shock loss on
momentum.
.'Momentum· = Momentum x M
M·
The components of an energy balance, Figure C-2, are evaluated at static equilibrium at the exit,
establishing exit momentum. The In-scale test results limit additional combustion of unburned
hydrogen and air to 20% of the air available. Iteration convergence of momentum between inlet
) and outlet is accomplished by adjusting entrained air flow.
.'
KSC-11495
-4A
8. ---Hl
HlOVapor
(:to'
H:
Air
------- HlOVapor
H20Liquid
183°F -.....
---- N,
10% H2 0
Oropou,
Figure C-2. Complex Duct Flow Chemistry which Quickly [nerts Unburned Hydrogen
Once the quasi-steady exit velocity for the abott condition is calculated, the transient air flow and
velocity can be determined. The duct loss coefficient dc;tenmnes the aspiration decay rate for the
entrained air. The resulting transient velocity curve is used to determine total air flow through
the dUCl A duct velocity balance is used to detennine conditions in the duct matching the
transient velocity. This calculated transient air flow is compared to the quasi-steady airflow at
me time of interest to detennine the air flow ratio. .
Figure e-3 displays validation of the momentum balance-calculation of quasi-steady velocities
900
800
700
600
~
;;.
1 500
~
8...
a
I 400
11
300
200
'00
0
('1'bousandl)
Helium Chamber Pressure. psig
0 Turbine Data 0
RPLDuctvet 6 Design PI
Figure C-3. Correlation between Analysis and Data/or S;ngleEng;ne Helium and Steam Tests
with K = 1
KSC-11495
-5A,
, • '00 2 ..
9. using data from the steam/one-engine helium flow tests aU::lifferent helium chamber pressures.
The chamber pressure can be increased to at least 10,000 psig without exceeding a duct exit
Mach number of .44. Figure 7-18 presents airflow versus chamber pressure for the same
conditions.'
Figure C..4 illustrates perfonnance of a series of simulated full-scale helium-steam tests.
Maximum entrained air flow occurs at 3900 psig and 16,1481bm/s, which is 83% of the 19,383
Ibm/s obtained during RPL. Engine momentum equal to RPL is reached at a helium pressure of
2474 psig, which supplies an airflow of 80% of RPL. These results indicate that helium is not
capable of pumping the volume of air obtained in the combustion process. The significance of
this result is that helium flow simulation of RPL conditions is not appropriate for study of
splash-back, since the appropriate air entrainment cannot be achieved.
20
o
18
16
14
12
~ ....Qi
~i 10
u.. .c:
~t:::.
8
6
.
2
0
0
c RPt o Max AJI Flow
Figure C4. Full-Scale Helium-Stiam Air Flow Less Than RPL
The duct exit Mach number is calculated at RPL conditions in response to concern that the total
flow is beginning to experience restriction due to velocity effects. The molecular weight of all
the gases is calculated for an exit temperature of 1830
F and yof 1.2 and 1.4. The resulting
average Mach numbers are 0.417 and 0.386, respectively. This reflects conventional duct design
philosophy and confinns that the duct is not too resaictive.
10
(Thousands)
Chamber Plessure. psig
4 Equal Momen"m
KSC-11495
10. The program listing ·':"-lO!'vlVEQ.FOR" contains the analYsis for the momentum
balance between ducl inlet and exit. Nain engine shoclt loss and additional
duct combustion are included.
C MOMVEQ.FOR
C
C CALCULATES DUCT EXIT NOMENTUM A.~D ITERATES TO 1'-tATCH INLET
C MOMENTUM. GIVES FULL SCALE EQUILIBRIUM VELOCITY WRT TIiwlE
C TOM LISEC 7-14-87
C
PROGRAN MOMVEQ
$ DEBUG
S STORAGE:2
OPEN(3,FILE='MOi'11.DAT',STATUS='OLD')
OPEN(4,FILE='INP.DAT',STATUS='OLD')
OPEN(5,FILE='MOf'-1.OUT',STATUS='NEi')
OPEN(6,FILE='MOM2.DAT',STATUS='OLD') .
OPEN(7,FILE='MON3.DAT',STATUS='OLD')
READ(4,*)XK,AIRFLO.TIS,TOS,AE,SMVIN,HWIN,X,RHOL,CPA,CPW,HYK,CPH,
+ N,DELT,TA,PA
WRITE(5,620)
620 FORMAT(IX,'TIlIE EQVEL XX AIRFLO BRAr XMVIN XNV XN
+ UH2 XMACHl')
650 FORl'otAT(F4.2,1X,F6.1,2X,F2.0,2X,F7.1,2X,F4.2,2X,F9.0,F9.0,F4.0,
+ 2X,F9.0,2X,F4.0)
DO 700 I =1,N
READ(3,*) T,XME1,VEl,XME2,VE2,XME3,VE3,~IVE1
READ(6,*) XMVE2,XMVE3,EMV,XME,UH2l,UH22,UH23,UH2
READ(7,*) TEEl,TEE2,TEE3,PCl,PC2,PC3
C LOSS MODIFIED EFFECTIVE DUCT FLOW AREA (FT2)
AEFF = AE /«1 + XK) **..5)
C ENGINE 1 MOMENTUM REDUCED DUE TO SHOCK
XNACHI = «2/(HYK-l»)*«pel/PA)** «HYK-l )/HYK)-l) )**.5
IF (XMACH1 .LT. 1.) COTO 160
STARM1 =( « (HYK+1)/2)* (XMACHl)**2)/( 1+( (HYK-l )/2)*XMACHl**2) )**.5
PCPRIM1 = PCl*(STARM1**2)**(HYK/(HYK-ll)/
+ «2*HYK/(HYI{+1»*(XlrIACH1)**2-(HYI{-1)/(HYK+1) )**
+ (l/(HYK-l)
~ x..~IPRIMl = «2/(HYK-l))*CCPCPRIMl/PA)**«HYK-l)/2)-l)U*.5
KSC-11495
-7A
12. C NOZZLE STEAM (LBM/SEC)
ST~tIN = X * HvIN
C ENGISE ~ASS FLOW COOLING HEAT REJECTION TO WATER (BTU/SEC)
HREI = XME1 * CPW * (TEE1 - TOS)
HRE2 = XNE2 * CPW * (TEE2 - TOS)
HRE3 = XME3 * CPv * (TEE3 - TOS)
C COOLING ENGINE EXHAUST TO !"IAKE STEA!'-l (LBM/SEC)
EECS = (HREI + HRE2 + HRE3) / 970
DO 99 Kli = 1,100
C HEATING INLET AIR BY CONDENSING STEAM TO l"IAKE NEW H20 (LBN/SEC)
HRAIR =AIRFLO * CPA * (TOS - TA)
HRAIR =HRAIR/970
C 02 BURNED AS F(H2) (LBM/SEC)
02 = 8. * UH2
C BURSED AIRFLO RATIO, IS IT 20% OR LESS OF AIRFLO
BRAT = 02*4.3l25/AIRFLO
IF( BRAT ~GT••20 ) THEN
02 = 0.2*AIRFLO / 4.3125
BRAT = .2
ENDIF
C CREATED EXCESS N2 (LBM/SEC)
XSN2 =3.3125 * 02
C NEWLY BURNED UH2
BH2 =02 / 8
C NEW STEAM (LBM/SEC)
XNS = 02 + BH2
C REMAINING UNBURNED H2
RUH2 = UH2 - BH2
C CORRECTION TO LOGIC FOR NO H2 FLOW
IF( UH2 .EQ. 0.0) UH2 = .0001 .
C COOLING REMAINING UNBURNED H2 TO MAKE STEAN
HRU21 = RUH2/UH2 * UH2l * CPH * (TEEI - TOS)
HRU22 = RUH2/UH2 * UH22 * CPH * (TEE2 - TOS)
HRU23 = RUH2/UH2 * UH23 * CPH * (TEE3 - TOS)
C COOLING SU~INATION
CRUH2 = (HRU21 + HRU22 + HRU23) / 970
KSC-11495
·-9A
13. C CONBt;STIOS AND COOLING OF AIR + UH2 (LBM/SEC)
C LOWER HEATING VALUE OF H2 =51571 BTU/LBN
HRCC =51571 * XNS/4.032 * 1/970
C SEW STEAM GENERATED (LBM/SEC)
XNNS = EECS + HRCC + CRUH2
C EXIT ~ASS FLOlv OF STEAM CONPONENTS (LBN/SEC)
STMOUT =STfvllN + XNNS + XNS - HRAIR
C i'ATER DROPLETS AT EXIT (LB!'vl/SEC)
HWOUT = .9 * HwiN" - STt-IIN - XNNS + HRAIR
C UNBURNED AIR (LBM/SEC)
AIROUT =AIRFLO - 02 - XSN2
C l'rlOLES OF MIXTURE
ETAH20 = STMOUT/18.02
ETAN2 = XSN2/2S.02
ETAAIR = AIROUT/2S.97
ETAH2 = RUH2 / 2.016
ETAT = ETAH20 + ETAN2 + ETAAIR + ETAH2
C MOLE FRACTION
XH20 = ETAH20/ETAT
XN2 = ETAN2/ETAT
XAIR =ETAAIR/ETAT
XH2 =ETAH2/ETAT
C flIXTURE MOLECULAR WEIGHT
XM = (STMOUT + XN2 + AIROUT + RUH2)/ ETAT
C AVERAGE GAS MIXTURE DENSITY (LBM/FT3)
RHOM = PA * 144 * XM/( 1545 * TOS)
C TOTAL DENSITY (LBM/FT3)
RHOT =RHOM * (STMOUT + HWOUT + XSN2 + AIROUT + Rt:H2)/
+(STMOUT + XSN2 + AIROUT + RUH2)
VEFF = (STNOUT + HlvOUT + XSN2 + AIROUT + RU'H2)/(RHOT * AEFF)
VEQ = VEFF / «1+XK) ** .5)
XMV = (ST~JOUT + HWOUT + XSN2 + AIROUT + RUH2) * VEFF
DELMV = XMVIN - x."'1V
IF(ABS{DELMV) .LE. (.OOOOOOl*XMVIN» GO TO 600
AIRFLO = (XNVIS/XMV)*AIRFLO
99 IF(AIRFLO .LE. 0.) GOTO sao
KSC-11495
~lO1-
14. WRITE(*,'(A)') 'CO~VERGENCE DID NOT OCCUR IN 100 PASSES'
600 CONTINUE
WRITE (5,650) T,VEQtXKtAIRFLO,BRAT,XMVINt~"'MV,X!vI,UH2,XMACH1
700 CONTINUE
GOTO 900
800 CONTINUE
WRITE(5,670)
670 FORMAT(lX,'BACKFLOW INMINENT - COVER THE DUCT!')
900 CONTINUE
STOP
END
.-
KSC-ll4·.9S
.-llA-:
15. The program listing "Dl"CTA.FOR" uses the quasi-steady duct ,·elocity and
duct loss characteristics to generate the transient duct velocity.
C DUCTA.FOR
C
C COMPARES TRANSIENT AND EQUILIBRIUM VELOCITIES DURING .-~ SS~IE
C PART SCALE OR FULL SCALE STARTUP-SHUTDOlvN EVE!'!T.
C TOM LISEC 1-27-87
C
PROGRAN DUCTA
S STORAGE:2
OPEN(3,FILE= 'DUCT.DAT',STATUS:'OLD')
OPEN(4 ,FILE='DUCT.OUT',STATUS='NEW')
PI =3.141593
A = 0
F =0
C
C SCREEN INTERACTIVE PROMPTS ----------------------------------------
WRITE(*,'(A)')' DUCT DIAMETER,FT '
READ(*,*) DEFF
WRITE(*,'(A)')' DUCT LENGTH,FT
READ(*,*) Xi..
WRITE(*,'(A)')' DUCT FRICTION DISSIPATION CONSTANT, FL/D-DLESS '
READ(*,*) XK '
WRITE(*,'(A)')' KINEMATIC VISCOSITY,FTA
2,SEC '
READ(*, *) XNU
WRITE(*,'(A)')' INITIAL TIME,SEC '
READ(*,*) TI
vRITE(*,'(A)')' FINAL TIME, SEC (ENTER O.IF VEL. FREQ. DEP.) ,
READ(*,*) TF
WRITE(*,'(A)')' TINE STEP, SEC (ENTER 0 IF VEL. FREQ. DEP.) ,
READ(*,*) DELT
WRITE(*,'(A)')' INLET VELOCITY, FT/SEC '
READ(*.*) VIN
WRITE(*,'(A)')' VELOCITY TRANSIENT AMPLITUDE, FT/SEC '
READ(*,*) A
WRITE(*,'(A)')' FREQUENCY, HZ '
READ(*,*) F
C
C PRINT FORMAT ------------------------------------------------------
WRITE(4,570) DEFF
570 FORMAT(/'DUCT DIAMETER: ',FIO.2,' FT')
WRITE(4,575) XL
5i5 FORMATe/'DUCT LENGTH:',FIO.2,' FT')
WRITE(4,578) XNU
578 FORMAT(/'KINENATIC VISCOSITY :',F10.8,' FT"2/SEC')
WRITE(4,579) A
579 FORi"lATC/'VELOCITY TRANSIENT AfvlPLITUDE =',FIO.2,' FT/SEC')
WRITE(4,580) F
580 FORNATC/'OSCILLATION FREQL1ENCY =',FIO.2,' HZ'//)
KSC-11495
16. WRITE(4,590)
590 FORMAT(7X,'TIME',7X,' K ' ,8X,'REYNOLDS',6X,'VEL.',4X,'EQ.VEL.',
+5X,'V/VEQ')
WRITE(4,592)
592 FORNAT(8X,'SEC' ,21X,'~O. ',4X,'FT/SEC' .3X' FT/SEC' /)
C
C i'rIAIN COMPUTATIONS
OMEG =2*PI*F
T =TI
-------------------------------------------------
V =VIN
C SELECTS DELT AND RUN Dt:RATION BASED ON FREQ.
IF( F .GT.O) THEN
TF =S/F
DELT =.1*F
ENDIF
620 RE = V*DEFF/XNU
C SELECTS FREQUENCY DEPENDENT TEST VELOCITY RELATIONSHIPS
IF(F .EQ. 0) GO TO 615
CALL SCA~VEQ(VIN,A,OMEG,T,VEQ)
615 CONTINUE
READ(3,*) N
DO 630 I=I,N
617 CONTINUE
READ(3,*) T,VEQ
DVDT = (I+XK)/C2*XL)*(VEQ**2-V*ABS(V»
IF(VEQ .LE. 0.0) THEN
VEQ =VEQ + 0.001
ENDIF
VRAT = V/VEQ
WRITE(4,600) T,XK,RE,V,VEQ,VRAT
600 FOR.NAT(2X,2(F10.2),F15.2,3(F10.2))
v = V +DELT*DVDT
630 CONTINUE
END
c
C FREQUENCY DEPENDENT EQUILBRIUN VELOCITY PROFILE
C
SUBROUTINE SCALVEQ(VIN,A,OMEG,T.VEQ)
VEQ = VIN + A*SIN(OMEG*T)
RETURN
END
C KSC-1149S
-13A
17. C FREQUENCY INDEPENDENT EQUILIBRIUM VELOCITY PROFILE
C
SUBROUTINE FULLVEQ(T,VEQ)
IF (T .LE. 0.15) THE!iJ
VEQ = 94.5 * (T/.15)
ELSEIF (T .GT. 0.15 .AND. T .LE. 0.25) THE!'
VEQ = 94.5 + 17.7 * «T-.15)/.10)
ELSEIF(T .GT. 0.25 .AND. T .LE. 2.) THEN
VEQ = 112.2 + 8.8 * «T-.25)/1.75)
ELSEIF (T .GT. 2••AND. T .Lh:. 2.15) THEN
VEQ = 121.0 - 121.0 * (T - 2.)/.15
ELSEr!"' (T .GT. 2.15) THEN
VEQ = O.
ENDIF
RETURN
END
KSC-11495
-14A
18. /~ The program listing "TVBAL.FOR" uses the transient duct ,·elocit~· for a
"elocity balance to determine total sirno,;.
C TVBAL.FOR
C
C CALCULATES DUCT EXIT VELOCITY AND ITERATES TO NAT.CH TRA!'>JSIEKT
C EXIT VELOCITY. GIVES FULL SCALE TRA~SIENT AIRFLOi ~RT TINE
C TOM LISEC, 8-20-87
C
PROGRA.~ TVBAL
$ DEBUG
$ Sl'ORAGE:2
OPEN(3,FILE:'MOM1.DAT'.STATUS:'OLD')
OPEN( 4,FILE:'INP.DAT',STATUS:'OLD')
OPEN(5,FILE:'TVBAL.OUT',STATUS:'NEW')
OPEN(6,FILE:'MOM2.DAT',STATUS:'OLD') .
OPEN(7,FILE:'MON3.DAT'.STATUS:'OLD')
READ(4,*) XK,AIRFLO,TIS,TOS.AE,SMVIN,HWIN,X,RHOL,CPA,Cpw,HYK,CPH,
+ N,DELT,TA,PA
WRITE(5,620)
620 FORl"tAT(IX,'TI~1E EQVEL XX AIRFLO BRAT XMVI~ ~"IV X!"I
+ UH2 XMACHl')
650 FORl"1AT(F4.2,lX,F6.l,2X-,F2.0,2X,F7.l~2X,F4.2,2X,F9.0,F9.O,F4.0,
+ 2X,F9.0,2X,F4.0) '"';
DO 700 I = l,N
READ(3,*) T,XMEI,VEl,XME2,VE2,DrIE3,VE3,X.1YIVEl
READ(6,*) XMVE2,XMVE3,EMV,XME,UH21,UH22,UH23,UH2
READ(7,*) TEEl,TEE2,TEE3,PCI,PC2,PC3,TVEL
C LOSS MODIFIED EFFECTIVE DUCT FLOW AREA (FT2)
AEFF : AE /t( 1 + XK) ** .5)
C ENGINE 1 MOMENTUM REDUCED DUE TO SHOCK
XMACHl : «(2/(HYK-I) )*( (PCl/PA)**( (HYK-l )/HYK)-l) )**.5
IF(XMACHI .LT. 1.) GOTO 160
STARMl = ««HYK+I)/2)*(X.~ACHl)**2)/(1+((HYK-l)/2)*XMACHI**2))**.5
PCPRIMI =PC1*(STARMl**2)**(HYK/(HYK-l»/
+ ((2*HYK/(HYI{+1) )*(L~CHl) '**2-(HYK-l )/ (HYK+1) ) **
... (l/(HYK-l))
XMPRI!wll =«2/(HYK-l»*( (PCPRIMl/PA)**«HYK-1 )/2)-1) )**.5
SRMPRMI =«(HYK+1)/2)*(XMPRIMI )**2/(1+( (HYK-l )/2) *(XMPRIM1 )**2»)
+ **.5
X!tIVEl : Xl"'IVEl * SRNPRMI/STARNI
GOTO 210
KSC-l149S'
-15A
20. C HEATING INLET AIR BY CONDENSING STEA!'-l TO NAIE NEW H20 (LBM/SEC)
HRAIR = AIRFLO * CPA i (TOS - TA)
HRAIR = HRAIR/970
C 02 BURNED AS F(H2) (LBN/SEC)
02 =8. * UH2
C BURNED AIRFLO RATIO, IS IT 20% OR LESS OF AIRFLO
BRAT = 02*4.3125/AIRFLO
IF( BRAT .GT••20 ) THEN
.02 = 0.2*AIRFLO / 4.3125
BRAT = .2
ENDIF
C CREATED EXCESS N2 (LBM/SEC)
XSN2 = 3.3125 * 02
C NEWLY BURNED'UH2
BH2 = 02 / 8
C NEli STEAM (LBM/SEC)
XNS =02 + BH2
C REMAINING 'UNBURNED H2
RUH2 = UH2 - BH2
C CORRECTION TO LOGIC FOR NO H2 FLOW I
IF(UH2 .EQ. 0.0) UH2 =.0001
C COOLING REMAINING UNBURNED H2 TO MAl.E STE»I
HRU21 =RUH2/UH2 * UH21 * CPH * ('ItEE1 - TOS'
HRU22 = RUH2/UH2 * UH22 * CPH * (TEE2 - TOS)
• HRU23 =RUH2/UH2 * UH23 * CPH * (~EE3 - TOS)
C COOLING SUMf.'lATION I
CRUH2 = {HRU21 + HRU22 + HRU23) / ~70
C COMBUSTION AND COOLING OF AIR + UH2 ~LBM/SEC)
C LOWER HEATING VALUE OF H2 =51571 BT'lf/LBM
HRCC =515i1 * XNS/4.032 * 1/970
C NEli STEAM GENERATED (LBM/SEC)
XNNS =EEes + HRCC + CRUH2
C EXIT MASS FLOW OF STEAM COMPONENTS CLBM/SEC)
STMOUT =STMIN + XNNS + XNS - HRAIR
C WATER DROPLETS AT EXIT (LBM/SEC)
HWOUT =.9 * HWIN - STMIN - X~NS + iHRAIR
C UNBURNED AIR (LBM/SEC)
AIROUT = AIRFLO - 02 - XSN2
-17A
21. C MOLES OF MIXTURE
ETAH20 = STNOUT118.02
ETAN2 = XSN2/28.02
ETAAIR =AIROUT/28;97
ETAH2 = RUH2 1 2.016
ETAT = ETAH20 + ETAN2 + ETAAIR + ETAH2
C MOLE FRACTION
XH20 = ETAH20/ETAT
XN2 = ETAN2/ETAT
XAIR =ETAAJR/ETAT
XH2 =ETAH2/ETAT
C MIXTURE MOLECULAR WEIGHT
XM = (STMOUT + XN2 + AIROUT + RUH2)/ ETAT
C AVERAGE GAS MIXTURE DENSITY (LBM/FT3)
RHOM = PA * 144 * Xl'tU(1545 * TOS)
C TOTAL DENSITY (LBM/FT3)
RHOT = RHOM * (STMOUT + HWOUT + XSN2 + AIROUT + RUH2i/
+(STMOUT + XSN2 + AIROUT + RUH2)
VEFF = (STMOUT + HWOUT + XSN2 + AIROUT + RUH2)/(RHOT * AEFF)
VEQ = VEFF / «1+XK) ** .5)
DELV = TVEL - VEQ
IF(ABS(DELV) .LE. (.OOOl*TVEL» GO TO 60~
AIRFLO = (TVEL/vEQ)*AIRFLO
99 IF(AIRFLO .LE. 0.) GOTO 800
WRITE(*,'(A)') 'CONVERGENCE DID NOT OCCUR IN 50 PASSES'
,600 CONTINUE .
WRITE(5,650) T,VEQ,XK,AIRFLO,BRAT,XMVIN,XMV,XM,UH2,XMACHI
700 CONTINUE
GOTO 900
800 CONTINUE
lvRITE(5,670)
670 FORMAT(lX,'BACKFLOlv IM~tINENT - COVER THE Dt!CT!')
900 CONTINUE
STOP
END
KSC-11495:
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22. REFERENCES
1) Shapiro, A. H. uThe Dynamics and Thennodynamics of Compressible Fluid Flow," Vol 1, pp
135·137~ The Ronald Press Company, New York, 1953.
,I e,..
2) Shapiro, A. H. "The Dynamics and Thennodynamics of Compressible Fluid Flow," Vol I. P
81. The Ronald Press Company, New York, 1953.
KSC-ll4~5
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23. 7.5 TASK V-DUCT TRANSIENT TESTS
7.5..1 Approach
The purpose of these teSlS was (0 determine whether duct
transient flow had a significant effect on the lesl condilions
that should be simulated for SIS demOnSlr1uion and 10 pro
vide sufficient data to calculate those condilions. A series 0;
KSC-11495
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24. leSIS was planned using helium at selected steady flow rates.
with the helium then to be shut off as rapidly as possible.
This I71S cxpected to give the opponunity to measure both
the steady now as a function of helium flQw rale and 10 give
a series of transient measurements with (he steam system
operating continuously. It v.-as realized that such sudden
shutoffs would excite organ pipe response oscillations in the
duct. but calculations indicated that the lowest organ pipe
frequency would be about 11 Hz. which would not interfere
with the measurements.
Unfonunately, the first tests showed that the duct organ pipe
frequency was much lower than expected. about 1 Hz. Fur
ther. the magnitude of the oscillations was so large that only
a qualitllive evaluation of the transient flow could be ob
tained. The wave speed in a duct. and consequently the
organ pipe frequency, is a function of the compressibility of
the fluid and extendabilil)' of the duct walls. Examination of
the duct revealed flat regions where a tow force of a few
pounds could move the duct wall an inch or so. Thus, an
unexpected result of the duct construction technique invali
dated the intended procedure for measurement of transient
flow.
This made necessary the use of a different measurement
technique. A hot-wire anemometer bad been installed at the
cnttance ofthe duct in the hope that it could be correlated 10
the lOW air flow. Results showed that it was completely
insensitive to the pumping of the helium jet. The measure...
ment could be correlated with the air flow pumped by the
steam jers. but could not be correlated wilh lOW air flow. A
turbine anemometer placed in the duct showed a good mea
sure of steady velocities. but its time conslant made impos
sibl~ the measurement of ttansient ~clocitics. A new test
was then added 10 the series. A hot-wire anemometer was
placed in the duct, near the turbine anemometer. Obviously.
steam flow could not be used. so the test us...--d helium only.
The bot wire was calibrated using the no-flow condition and
the s&Cady-state reading of the turbine anemometer. The hot
wire shows some fluctuation because of the organ pipe ef
fect. but the effect is minor compared to the effcct on the
measured duct impact pressures (which arc referenced 10
external ambient pressure).
7.5.2 Duct Loss Coefficient
Figure 7-12 presentS the measured duct velocity transient
using a hot-wire anemomelCr at Zone O. Superimposed are
the equilibrium (quasi-steady-state) velocil)' caused by the
helium jet and a calculation of the transient velocity using a
duct loss coefficient of 1.0. The duct loss coefficient 'is
defined to be the friction loss in the duct divided by the duct
dynamic pressure. NOle that it does not include the duct exit
dumping loss. The agreement between measured and calcu
lated duct velocity is c!:-tceUent for both buildup and decay of
150
If!,,.,nf1
' • • • • E........b'....n Vt!luCII"
" / ~ - , Mr..."u't!d V~lo,.IV120 ............j';.i;J,.r· _..-:. - - - T...." ...nl V..luC""
:., ",. I ' . : to. 1(. ,
: 1/ :
- 90 II :.
I • :
~ i
I' :
~ ~ 60
; ~
;~30
rO~--------------~----------------
o 2
Figure 7-12 Duct Transient Flow (Helium Only,
Run JJ)
flow through the duct. Thus. at least for the flow wilhout
steam. the existence of transient flow is clearly demon
strated, and a duct loss coefficient of 1.0 characterizes the
flow through the duct. The duct loss coefficient should be a
characteristic of the duct geometry and YOuld not be ex
pected to change with the fluid in the duct. To confirm this
invariance. pressure data from the transient run with the
.
least organ pipe effect. Test 34, was compared with tran
sient calCulations. Figures 7·13 through 7-15 compare ve
locities computed from measured impact pressure at several
Zone 0 locations with transient velocities computed for
duct loss coefficients of 0.0, 1.0, and 3.0. Although the
results arc distorted by the organ pipe effect, a value of 1..0
is consistent with the measured pressures.
7.5.3 Transient Effect
The evaluation of the transient effect for shutdown from
RPL is made diflicult by the fact that a good deal of uncer
tainEy exists concerning the eqUilibrium flow conditions at
RPL. and even more uncertainEy existS concerning the
quasi-steady tlow during the shutdown.. A program has been
written that evaluates duct inlet momentum from the
SSMEs. including shock losses. and from the steam jets.
Empirical equations from lCStS calculate the hydrogen com
bustion in the dUCI inlet. A heat balance determines the
water evaporated in the duct. A duct pressure loss is ap
plied. and the dUcl air aspiration is iterated until the exit and
inlet momentum are balanced. This makes possible a con
sistent calculation ofquasi-steady ducl velocity during shut
down from RPL. Then the transient duct velocity and the
additional aspirated air due to the transient flow can be
calculated. Figure 7·16 shows the results of these calcula
tions during shutdown from RPL. Appendix C conr.ains
program listings and a discussion of the theory used.
KSC-11495
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25. 200
Me.sured Velocity
- -. C.llcula.ed Trlln,;enc Velocity
••••• Equilibrium Velocity
150
V.locity.
his
100
50
......•..•..•..........••.•..•....•.•.•
O~-----------------r-----------------T----------------~----~--~------~------
·0.5 o 0.5 1.0 1.5
Tim•• s
Figure 7·13 Duct Transient Flow-Location 20 (Helium and Ste..m. Run 34)
200
M.....red V.'Dcity
Calculated Tr.nsient VelDcity
••••• Equilibrium Velocity
150
~,oo
1...>
50
o
·0.5 o 0.5 1.0 1.5
Figure 7·1-1 DUCI Tralls;t!llt Flow-Locatioll 21 (Helillm i111d Steam. RlIlI 34) KSC-11495
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27. All of these calculations use a dUCI loss coefficient of 1.0. helium pressure on duct flow. Figure 7-18 presenls calcula
The 3spiraled air flow 3( RPL is calculated (0 be over lions tor 3ir flow as a funclion of helium pressure. The air
19.000 Ibis, about six limes the mass How of the three .low increases with helium pressure up to a value of 10.000
SSMEs. NOlO that the aspiraled air now does not have the psi. Bcc:ause general duct bacldlow could not occur unlil
smooth character associated with lhe decrease ofduct veloc even higher helium pressures were reached. this strongly
ity. The air flow also refleclS me changing composition of suggests that the observed backflow must be a consequence
me flow. For instance, from time := 0 to :about 0.8 seconds. of local flow conditions. Specifically. the proximity of the
air flow increases to compensate for the sudden drop in No. 1 engine to the west wall makes it probable that a
engine flow. locally separated flow is the cause of the splashback. Ap
pendix C. Figure C-2. presents data correlation with analy
The paramecer of interest to me design of the steam inening ses which substantiate the calculation of airflow as a func
system is the ratio of the transient air flow to the quasi tion of helium pressure.
Slcady-state airflow. Figure 7-17 presents this ratio for the
entire shutdown process. The design point for the SIS is the
time at which the last engine reaches an oxidizer-to-fuel
ratio of one. the condilion for which combustion inside the
engine ceases. This design poim is reached at 4.0 seconds.
and the air flow ratio at this time is 2.SS.
7.5.4 Observed Splashback
During the highest helium pressure test (Run 35), a signifi.
cant water backtlow was observed. Concern about the cause
ofthis backtlow prompted an analysis of the effect of nozzle
3.5
3
,..":I
••
2.5
~•::I
0.... 2
..C
•
...•c
...
!i.
';
a:
0.5
O~--------r-------~--------T-------~--------~-------r--------r--------r
o 2 6 8
Time. I
Figure 7-17 Predicted Air FloUJ Ratio duri"g Sh,ltdowIl from RPL
KSC~~~49~
-:-24:A-.
28. 260
1/7·Sc.l. Entrained Air
240 SingI. Engine Helium and St.am, K-l
220
200
180
110
140
100
10
20
O~----~__----~----~------~----~------~----~------~----~------r-----~----~
o
IThCKI..ndU
Helium elMm..., Preuure. paig
Figure 7-18 Predicted Effect ofHelium Pressure on Duct Air Entrtlinment
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